Undergraduate Papers

04/26/13

Amanda Balough

Understanding Humanity through Dolphin Studies

Over the decades, scientists and researchers have conducted cross-species studies to better understand and define what it means to be human. Researchers have conducted previous studies on primates, hyenas, and crows. Not a lot of work has been done on dolphins in comparison to humans. Due to new and improved equipment, researchers now have the capability to conduct more efficient studies and gather quantitative data for dolphin studies. The quantitiatve data can then be used to compare and contrast dolphins and humans. This research focuses on the dolphin brain, dolphin language, and dolphin tool use in comparison with homo homo sapiens.

The dolphin’s brain is the second most powerful and complex brain in animals, next to the human brain. Dolphins have a large brain and large brain animals like humans, chimpanzees, and dolphins have a number of things in common. They generally live long lives, form stable communities, live in fluid social groups, and demonstrate total parental dependence during childhood. An appropriate IQ test to measure dolphin intelligence does not exist. It is impossible to fully assess the animal’s level of intelligence in this manner. But another way which has been suggested to measure intelligence is by determining the measure of relative brain size defined as the ratio between actual brain mass and predicted brain mass for an animal of a given size. This is called the “encephalization quotient”, or EQ. This measurement suggests the higher the number, the greater the intelligence. The human EQ is 7.0. The EQ for great apes, elephants, chimpanzees and whales is about 1.8-2.3, meaning they have smaller brains for their body size than do humans. The dolphin’s EQ is 4.2, the closest EQ ratio to the human than any other animal.

Additionally, the degree to which the cerebral cortex is folded appears to be a measure of intelligence. The more folded the cortex, the more room within the brain to house additional neurons. The only animal to have a more folded cortex than man is the dolphin. The theory most commonly accepted is that the larger brain evolved to support more complex cognitive abilities. Dolphins can remember events and learn concepts, changing their behavior as a result of previous experience. They can communicate with each other during cooperative behaviors, manage relationships in their pods and raise their young. They can understand not only symbolic language words but can interpret the syntax order of language. This understanding of syntax is highly indicative of intelligence. Signature whistles produced by dolphins serve to offer some evidence that dolphins have a self-awareness, or the capacity to have a concept of “self” and to know that one exists as an individual being. Self-awareness exists in the brain’s pre-frontal cortex. Other than in dolphins, self-awareness appears to exist only in large brained primates and man. It has long been suspected that dolphins have the ability to recognize individuals and objects, remember tasks, problem solve, adapt to change and learn complex tasks. Research done at the Department of Neuroscience at Mount Sinai Medical School proves spindle cells are present in the dolphin brain, as well, giving credence to these suspicions.

Dolphins, like humans, are capable of behavioral mimicry. In other words, they can imitate behaviors demonstrated by their human trainers. If a human raises his leg, the dolphin can recognize the relationship the human body part has to its own anatomy and will raise its tail. This indicates the animal can associate a part of its anatomy with the human form. It can also mimic another dolphin. This is demonstrated by the performance of synchronous behaviors. If one dolphin is about to perform a jump, another animal can copy this behavior and jump at the same time with this animal. One dolphin is said to act as a “demonstrator”, while the other animal is the “imitator” of such behaviors

Dolphins are also able to interpret televised behaviors and to respond to gestures shown on the screen upon being exposed to television for the first time. This is the first demonstration in any animal species of behavioral response to televised gestures. Dogs, cats and chimpanzees have not shown such responses in similar research protocols. We now realize they are visual specialists as well, using both sight and sound to succeed in their aquatic environment. Dolphins have also been shown to recognize themselves in a mirror, using what is called “contingency testing”, or making movements while examining themselves for this movement. This finding is unexpected as dolphins primarily experience the world through sound and their echolocation system would not function in a mirror reflection. They are aware of their own recent behaviors and can repeat a behavior or, when asked by a trainer, perform a behavior which has not been performed recently. Dolphins can maintain a mental image of the behavior it last performed and update that image as each new behavior is performed, repeating the latest behavior in this sequence when requested. Dolphins respond to a trainer pointing to an object. Not only do dolphins understand and respond appropriately to a human pointing directly at an object, they respond appropriately to a cross-body point. An example of an appropriate response to pointing would be to retrieve an object to which the trainer points or to move an object from point “A” to point “B”. Dolphin’s can also remain attentive for long periods and to make rapid discriminations between critical and non-critical images and sounds with a high degree of accuracy.

Besides being aware of themselves, dolphins experience basic emotions, engage themselves in some degree of abstract, conceptual thought, choose their actions, learn by observing, understand the structure of their environment, learn what works and what doesn’t by solving problems, and create new solutions to problems with which they are presented. When interacting with man, they appear to recognize the difference between children and adults and tend to be more gentle and patient with children.

All of these characteristics can be seen in the human species. However, there is not a lot of evidence to dolphin language. Do dolphins have a language? This is a fantastically interesting question, and one that researchers at the Dolphin Communication Project are asked on a regular basis. There are three important definitions or meanings for the word ‘language’ that are relevant to the question ‘do dolphins have a language’. The first meaning is ‘language’ as a kind of metaphor or simile. When we say ‘the language of love’ or ‘the language of dance’ we don’t mean that dance is the same as a spoken language like English or Chinese. The second more formal definition of ‘language’ is that used by linguists and other cognitive scientists. It is the kind of definition you will find when you look up the word ‘language’ in the dictionary, like ‘language’ is defined as an arbitrary set of learned symbols organized systematically into a logical grammar consisting of small infinitely combinatorial elements, capable of communicating concrete and abstract meaning, and shared by a group.” The third and final definition is that the meaning and usage of the word ‘language’ deems language to be any form of communication system.

Essentially this ‘informal’ definition of language is simply ‘a communication system’. For the informal version, the researchers said that dolphins have a language. Dolphins, like nearly every living thing on the planet, communicate with each other. So if the question is ‘do dolphins have a communication system’, then obviously the answer is yes. Things got interesting when the researchers wanted to know if the communication system used by dolphins is anything like the formal definition of language. However, to determine if dolphins have formal language compared to humans is much more difficult, for human language is a supremely remarkable thing. It is far more than simply a complex system of communication. It is controlled by a mostly unconscious set of rules that allow a human to learn, speak, and understand language; what Steven Pinker calls ‘the language instinct’. Many linguists think that a complex set of language rules are present in the human brain at birth, and as a child grows and is exposed to whatever natural language its parents are s speaking, these rules are modified and adjusted; forming themselves around the linguistic input, allowing the child to learn a language. Learning a language, unlike the kind of learning it takes to tie our shoes, is something humans do spontaneously. The rules that govern human languages are, deep down, all the same. Humans can also use language to refer to things in our environment. This is a basic property of human language that is unlike anything found in normal animal communication systems. Even more impressive, humans can also talk about abstract concepts like greed, fire prevention, and secularism.

But what about dolphins? Like all animals, dolphins have evolved a set of behaviors that allow them to communicate. Like humans, they use a variety of kinds of physical contact for communication, for example: a gentle nuzzle, a playful bite, an aggressive bite, a soft petting, or a smack to the head. They also use visual signals, like human gestures, to convey information.

Dolphins, like chimpanzees, birds and many other animals, also use vocalizations for communication. They produce whistles, creaks, chuffs, screams, squawks, pops, chirps– a whole assortment of sounds that scientists have labeled in any number of ways. Dolphins appear to use these communicative behaviors, vocalizations, physical contact, and postures, to express all sorts of things to each other. They can communicate their emotional, but also convey information about their reproductive state, age, gender, etc. What’s more, dolphins, like many animals, can learn to read each other’s behaviors and communicative signals in order to coordinate activities like feeding on fish, or even just swimming together.

However, do dolphins have anything like human language’? The simple answer to that is: as far as science has been able to determine, no they don’t. “Following from the previous discussion, scientists at this point have no reason to believe that, unlike human language, the natural communication system of dolphins can do the following things: refer to objects in their environment, refer to abstract concepts, combine small meaningful elements into larger meaningful elements, organize communicative elements into a systematic grammar that can produce an infinite combination of meanings, refer to things in the past and the future, and learn and store in memory the meanings of hundreds of thousands of concepts and map them onto specific combinations of vocal patterns. “Dolphins can be taught artificial communication systems that allows them to do at least some of the things listed above, but, despite their prowess in these experiments, dolphins don’t seem to use their normal communication system to do any of the human language. In fact, no animal communication system are able to do any of these things, and certainly no system other than human language can do all of them” says Dr. Sweeting.

While dolphins may not possess the brain power and the abilities to have a ‘language’ like humans do, they do have the ability for tool use. On July 20, 2011, wild dolphins used marine sponges as tools to find food they cannot easily detect through echolocation, according to a new study published by Georgetown researchers in the July 20 issue of the online journal PLOS ONE. Georgetown’s Eric Patterson, a Ph.D. in biology candidate, and longtime dolphin researcher and Professor Janet Mann published the study 26 years after the discovery that dolphins use tools to forage for prey. The study was funded by the National Science Foundation, the National Geographic Society and Georgetown University. “Tool-use has long fascinated us, especially since we are the quintessential tool-users and it was once believed to be a hallmark of humankind,” Patterson explains. “But some primates, elephants, birds and other species also use tools, and studying why and how they do so provides insight into the context in which tool-use arises.” Most wild animals that use tools do so to extract food from difficult to reach places and Shark Bay bottlenose dolphins in Western Australia are no exception. “These dolphins rip up marine basket sponges that grow along the seafloor and then wear them for protection when scouring the rough substrate for prey,” says Mann. A staple for the sponging dolphins is the barred sandperch, but the mammals cannot detect it through echolocation because the fish lacks a gas-filled organ called a swimbladder. Most fish have swimbladders, which helps control their buoyancy. Bottlenose dolphins are able to detect the gas chamber through echolocation. By using the marine sponges to uncover the sandperch, Patterson and Mann show that the dolphins use the sponge tool to easily access the fish without injuring their beaks on the rough seafloor below. “Sponging dolphins seem to specialize in hunting these swimbladderless prey when compared to the rest of the Shark Bay population,” says Mann, who has been studying the bottlenose dolphins there since 1988.

Patterson says the researchers believe the small size of the prey explains why “spongers are the workaholics of the bay – they have to hunt often in order for this small-yet-reliable meal to be enough, but it seems to work for them since they are able to pass the method down for generations. Nearly all of the female Shark Bay dolphins that live in channels that are 7 to 12 meters deep specialize in sponging. “These clever dolphins have figured out a way to exploit fish that other dolphins cannot,” Mann says. “This highlights the dolphins’ innovative and problem-solving ability, which has been well-demonstrated in captivity, but less so in the wild. Mann also notes that her research team’s previous work has demonstrated that dolphin mothers pass the sponging method down to their daughters and some of their sons. So far, the team has documented three generations of spongers. “This tradition is highly specific to the micro-habitat spongers live in, demonstrating the importance of ecology in the evolution of tool-use and culture,” she says.

So dolphins have the capability to have an informal form of communication, a highly adaptive brain that balances social functions and the echolocation system, and learned behavior as displayed through the usage of tools. But like humans, dolphins are not as friendly and harmless as they appear. Researchers found the marine mammals lead complex social lives, living in an “open society” where regular homosexual and bisexual relationships are found. The conclusions from the international team of scientists came after they spent the past six years studying the behavior of 120 bluenose dolphins in Shark Bay, Western Australia. In one of the most extensive studies of its kind, male bottlenose dolphins were also found to organize gang-like alliances, in which they guard females against other groups. In some instances, males would assert their authority by forcefully mounting other males and other such violent sexual behavior. This was viewed as a short-term show of strength in order to dominate males from other groups. As they recorded their movements, others were observed to steal fertile females away. While most animals formed alliances to defend their territory, the study did not find any evidence of this. During their observations, they did find animals roamed hundreds of square miles in which they often encountered other dolphin groups. Reporting in the journal Proceedings of the Royal Society B, they concluded the highly intelligent mammals lived in an “open society”. Prof Richard Connor, the study’s co-author, said dolphins would have to be incredibly intelligent to understand the “soap operatics” of their lives. “I work on the male dolphins and their social lives are very intense,” he told Discovery News. “It seems there is constant drama. I have often thought, as I watched their complicated alliance relationships, that their social lives would be mentally and physically exhausting. “It seems there is constant drama. I’m glad I’m not a dolphin.” Prof Connor, a biology professor from the University of Massachusetts, Dartmouth, added that rather than males guarding a specific territory, groups have a “mosaic of overlapping ranges”. Prof Connor, who first began his studies of the Shark Bay dolphins in the early 1980s, said that while males were “capable of serious aggression,” they did not constantly row and did not patrol and defend particular areas. In their latest study, researchers found that the dolphins lived in an “open society” where allies were swapped with remarkable frequency. Alliances were found to be switched as dolphins battled against larger, tougher challengers. The dolphins were all tagged and given names, such as “Captain Hook” and “Flat Fin” that were based on the shape of their fins. The team found dolphins also organized themselves into three different kinds of groups that could overlap. One group, usually in pairs or threes, was tasked with gathering fertile females during mating season. In a “second-order alliance”, the animals form “teams” of between four and 14 males which mount attacks on other groups to take their females, or to defend against attacks. The third group maintained “friendly relations” with all dolphin groups and helped out various teams when additional forces were needed. The team found the males made a series of alliances with the same sex. They only observed one group of females forming a temporary coalition against young males. Only humans and the Shark Bay bottlenose are known to have these multiple levels of male alliances in their social network. Dr Nichola Quick, a researcher at the University of St Andrews’ Sea Mammal Research Unit, said that understanding how animals managed social interactions in the wild was crucial in order to “truly understand their behavior”. Researchers studying dolphin behavior have discovered rogue packs of adult male dolphin’s gang raping swimmers in open waters. Human decoys fitted with tracking devices have been dumped in open waters and observed form a helicopter. Scott Randleston of the Dolphin Research Institute of Boca Raton said “In every case the decoy was set upon in a short time by groups of dolphins ranging from 8 to 10 young males. It seems there are gangs of dolphin predators roaming the open waters looking for humans to sexually assault. The dolphins in each case were observed circling the swimmer as one of the group grabbed the swimmer with their penis and dragged them under, then the others followed. Dolphins have a prehensile penis, it is full of powerful muscles and they can wrap is around objects, such as a human limb. The decoys never resurfaced in any of the studies….We tracked on of the decoys to an underwater case where is had been repeatedly raped and torn apart by the dolphins.”

In comparison with chimpanzees, dolphins have an uncanny intelligence that is only rivaled by that of a humans. However, that being said, humans have more complex systems than a dolphins and with the aid of dolphin studies, researchers are being able to better understand what it means to be human. Concerning the brain, dolphin brains and human brains are very similar in size. Due to the size of their large brain, dolphins generally live long lives, form stable communities, live in fluid social groups, and demonstrate total parental dependence during childhood. Very much like humans, dolphins are ‘programmed’ to be group creatures and form social bonds. These social skills allow dolphins to live and function as a large body, in which social cliques and even gangs are formed. While dolphins and humans have a big brain, much of the human frontal cortex is dedicated to speech and social form, while much of the dolphin frontal cortex is dedicated to their echolocation system. Thus being said, dolphins do not have the capacity for full language, but they do have the ability to communicate through complex clicks, whistles, and whirls.

Dolphins also have the brain power and knowledge to use tools. Unlike humans, who create tools out of other tools, dolphins use materials that they find to assist them in a task; and while dolphins may live in large social groups, they are unable to organize a group of dolphins to complete a task using tools which humans are able to do. The abilities to organize into groups is a very advantageous skill for organizing pods, groups for herding fish, and mating cliques (Schaefer). It is in these mating cliques that dolphins will create groups of bachelors and bachelorettes. However, sometimes the bachelors will stick together after the mating season and roam the oceans looking for potential mates, even if those mates are unwilling. Rape is common in dolphins and in humans, revealing that both species have a vicious streak. It is uncertain if dolphins have the capacity for war, but groups of male dolphins have been documented attacking and killing other pod males and taking the fertile females. These traits of attacking and stealing away other fertile females are also present in Homo sapiens. While our species may take it to the extreme with all our war, aggression, especially sexual aggression, has been documented in human beings. Some may argue that aggression is fueled by the need to protect ones person and lineage, but that does not justify rape. If other species are display this trait, how deep do aggression run in our genetics? Is there a certain code for aggression?

How do we define what it means to be human? In comparison to dolphins, our ability to have a language gives us a great advantage. Our greater brain size allows us to function as a larger group than that of the dolphins, and because we don’t have to dedicate as much brian power as they do to navigation, we are able to utilize that brain power for other functions, such as language, social structure, and learning. Our ability to utilize tools to create other tools is still unsurpassed, even by the dolphins. But humans do still have the animalistic tendencies that make other humans cringe. The ability to rape is found in other species, like dolphins. However, dolphins are one of the few species that have been known to rape other species, such as humans. Again, this goes back to the question, how do we define what makes us human. Scientists have agreed that one of the ways to define what makes us human is our ability to create a language.